Month: December 2018

“batteries for electric bicycles -electric bike motors and batteries”

I am working on a similar project, and was wondering if the BMS’s that you recommended would handle any back EMF from the motor (from regenerative braking, for example.) I see that there are separate leads for charging and discharging, so I’m guessing if current flowed back through the discharge circuit that would be bad. Do you have any recommendations on a BMS (or something different) that would handle this condition? You would think they would help with cooling, but in reality there is little to no difference. They do create an air gap between cells but because that air is trapped inside the pack and can’t get out, it just turns into an oven. So you can glue your cells together and have them cook on a skillet or use those plastic spacers and have them bake in an oven 😉 2. Agreement to Rules: By participating, you agree to be fully unconditionally bound by these Rules, and you represent and warrant that you meet the eligibility requirements set forth herein. In addition, you agree to accept the decisions of Electric Bike Technologies LLC, as final and binding as it relates to the content. The Sweepstakes is subject to all applicable federal, state and local laws. Why does this formula work? Think about it: heat shrink (unless stated otherwise) usually has a 2:1 shrink ratio, so if I...

Read More

“bike battery packs _ebike battery pack”

I love this article and I am inspired by the knowledge here, I have a question, I need to build a 72v battery and the one I’m looking at is using 38160 cells, these cells are very expensive so how can I manage this the best using the smaller normal size cells like you’re using! Do I really have to make a battery 20 cells deep to reach this and to bump up the amp hours I would let say go 10 wide for a 30 amp hour right? Pretty close! Big battery but is it feasible or is there a better product Question: If put two connectors at the controller end (creating a possible parallel connection) plug in the “Whale” charger at 17.5 Amp and turn it on to pre-load and open the controller, and then on the second parallel connector plug in the 20 amp “Ebay” battery (both “Ebay” and “Whale” are li-ion, 48v but different ampages and cell manufactures: Panasonic and Sanyo). A High-performance Motor acheives a top speed of 20-30km/h with a range of 20km means your ebike commute just got easier. Folding style, portable convenient, easy storage. You can lock your bike by ap… Thank you so much for taking the time to write the battery chemistry article. I am looking at buying my first electric bike, and needed to understand the differences in...

Read More

“bicycle battery kit _bike batteries online”

I’m glad you enjoyed the article. To answer your questions: I chose this type of battery instead of LiFePO4 mostly because of the cost and convenience. LiFePO4 is a bit more expensive and has fewer options for cells. These Li-ion cells are a bit less expensive and there are dozens of options with many different specifications for any power/capacity need. I’ve used and built LiFePO4 packs before and they have their own unique advantages, but for me they just don’t add up to enough. LiMn/LiMnO2-Lithium Manganese Oxide. Adding manganese to the cathode made this chemistry more stable and less sensitive to individual cell balancing issues. If you were using LiFePO4, and one cell began losing its amp-hour capacity, the rest of the pack would get dragged down to the weakest cells level. Demanding high amps with one weak cell in the pack would cause the entire pack to wear out much earlier than it should have.  With LiMn, the packs just seems to stay in balance, with all the individual cells aging equally. 3. Lastly, I assume if the BMS & battery were able to produce the 50A X 24V watts of 1200W that my electric motor would only ever use the 500W it is rated for? As in the E bikes controller would only draw around 500W? It’s hard to say for sure without seeing your work. I...

Read More
  • 1
  • 2